The University of Iowa Institute for Vision Research, Iowa City, USA.
University of Iowa Department of Ophthalmology and Visual Sciences, Iowa City, USA.
Sci Rep. 2018 Sep 6;8(1):13387. doi: 10.1038/s41598-018-31846-z.
Age-related macular degeneration (AMD) is a common, blinding disease associated with increased complement system activity. Eyes with AMD show elevated accumulation of the membrane attack complex (MAC) in the choriocapillaris and degeneration of macular choriocapillaris endothelial cells (ECs). Thus, one could reasonably conclude that the endothelial cell death that occurs in AMD is due to injury by the MAC. We therefore sought to identify strategies for protecting ECs against MAC lysis. RF/6A endothelial cells were pre-incubated with a library of FDA-approved small molecules, followed by incubation with complement intact human serum quantification of cell death. Two closely related molecules identified in the screen, econazole nitrate and miconazole nitrate, were followed in validation and mechanistic studies. Both compounds reduced lysis of choroidal ECs treated with complement-intact serum, across a range of doses from 1 to 100 µM. Cell rescue was confirmed in mouse primary choroidal ECs. Both exosome release and cell surface roughness (assessed using a Holomonitor system) were reduced by drug pretreatment in RF/6A cells, whereas endosome formation increased with both drugs, consistent with imidazole-mediated alterations of cell surface dynamics. The results in the current study provide further proof of principle that small molecules can protect choroidal ECs from MAC-induced cell death and suggest that FDA approved compounds may be beneficial in reducing vascular loss and progression of AMD.
年龄相关性黄斑变性（AMD）是一种常见的致盲性疾病，与补体系统活性增加有关。AMD 眼的脉络膜毛细血管中出现膜攻击复合物（MAC）的积累增加，黄斑脉络膜毛细血管内皮细胞（ECs）退化。因此，可以合理地得出结论，AMD 中发生的内皮细胞死亡是由于 MAC 的损伤。因此，我们试图确定保护 ECs 免受 MAC 溶解的策略。用 FDA 批准的小分子文库预先孵育 RF/6A 内皮细胞，然后用补体完整的人血清孵育，定量细胞死亡。在筛选中确定的两种密切相关的分子，硝酸益康唑和硝酸咪康唑，在验证和机制研究中进行了后续研究。两种化合物都能降低补体完整血清处理的脉络膜 ECs 的溶解，剂量范围为 1 至 100μM。在小鼠原代脉络膜 ECs 中证实了细胞挽救。药物预处理可降低 RF/6A 细胞中的外泌体释放和细胞表面粗糙度（使用 Holomonitor 系统评估），而这两种药物均可增加内体形成，这与咪唑介导的细胞表面动力学改变一致。本研究的结果进一步证明了小分子可以保护脉络膜 ECs 免受 MAC 诱导的细胞死亡，并且表明 FDA 批准的化合物可能有益于减少血管损失和 AMD 的进展。
